New thermosets obtained by copolymerization of DGEBA with 1,5,7,11-tetraoxaspiro[5,5]undecane catalyzed by lanthanide triflates

Crosslinking study of mixtures of DGEBA and 1,3‐dioxan‐2‐one catalyzed by lanthanide triflates

“…In a previous paper,18 we studied the curing of mixtures of DGEBA epoxy resin with a SOC, 1,5,7,11‐tetraoxaspiro‐5,5‐undecane (TOSU), in an attempt to obtain thermosets with breakable carbonate groups in the polymeric chain and a low shrinkage during curing. The overall shrinkage measured was low, and in one of the mixtures studied, expansion was even observed to take place.…”

“…The present study deals with the copolymerization of a cycloaliphatic carbonate, 1,3‐dioxan‐2‐one (TMC), with epoxy resins promoted by lanthanide triflates as cationic initiators. Lanthanide triflates have proved to be excellent Lewis acid initiators that are stable in water and environmentally friendly catalysts15 capable of copolymerizing lactones16, 17 and SOCs18 with epoxy resins.…”

Phosphorus-containing thermosets obtained by cationic copolymerisation of glycidyl compounds with a spiroorthoester or γ-butyrolactone

“…Although typical crosslinking of epoxy resins are generally accompanied by a significant volume shrinkage (above 3%, depending on the crosslinking mechanism) [7,34], in all mixtures of glycidyl compounds with SOEs studied, the observed positive values of DV are much lower than those observed in the crosslinking of pure DGEBA with ytterbium triflate (about 3%) [19,35]. In the analogous samples obtained from lactone, in which the SOE is formed ''in situ'', the shrinkage is higher because the formation of SOEs from lactone and epoxide takes place with contraction.…”

Crosslinking of mixtures of diglycidylether of bisphenol‐A with 1,6‐dioxaspiro[4.4] nonan‐2,7‐dione initiated by tertiary amines: III. Effect of hydroxyl groups on network formation

“…There has been considerable interest since the 1970s in developing crosslinkable monomer systems with reduced shrinkage or even with positive expansion 1. One of the main objectives of our research group for the last few years has been the control of shrinkage of epoxy oligomers by cationic copolymerization with other ring‐opening monomers 2–4. There are two main methods by which this can be achieved.…”